园林植物配置与绿化养护管理措施

园林绿化工程施工过程之中,植物配置以及绿化养护管理是非常重要的一项工作,合理化的植物配置以及精细化管理将会对园林景观的造景效果产生积极影响,城市园林绿化也是城市建设过程中的重要内容,所以要从理论与实践进行深度融合的维度切入,高度注重园林植物配置以及绿化养护工作,积极引入现代化先进技术,切实提升园林绿化植物管理水平,进而满足城市园林工作日益多元化的发展需求。基于此,本文在研究分析的过程之中,围绕园林植物配置与绿化养护管理措施这一论题展开深入化、全面化的探析,旨在进一步提升园林植物配置以及绿化养护管理水平,促进城市高质量发展。

园林绿地建设养护管理的实施策略

园林绿化工程中养护管理工作有着十分重要的作用,这项工作具有长效性、持续性的特点,并且这项工作对技术有着较高的要求。本文就园林绿地建设养护管理的实施策略展开论述,以供参考。

Islet transplantation and antioxidant management: A comprehensive review

Islet transplantation as a promising treatment for type 1 diabetes has received widespread attention. Oxidative stress plays an essential role in cell injury during islet isolation and transplantation procedures. Antioxidants have been used in various studies to improve islet transplantation procedures. The present study reviews the role of oxidative stress and the benefits of antioxidants in islet transplantation procedures. The bibliographical databases Pubmed and Scopus were searched up to November 2008. All relevant human and animal in-vivo and in-vitro studies, which investigated antioxidants on islets, were included. Almost all the tested antioxidants used in the in-vitro studies enhanced islet viability and insulin secretion. Better control of blood glucose after transplantation was the major outcome of antioxidant therapy in all in-vivo studies. The data also indicated that antioxidants improved islet transplantation procedures. Although there is still insuffi cient evidence to draw definitive conclusions about the efficacy of individual supplements, the benefi ts of antioxidants in islet isolation procedures cannot be ignored.

Antioxidant therapy in the management of acute,chronic and post-ERCP pancreatitis:A systematic review

We systematically reviewed the clinical trials which recruited antioxidants in the therapy of pancreatitis and evaluated whether antioxidants improve the outcome of patients with pancreatitis. Electronic bibliographic databases were searched for any studies which investigated the use of antioxidants in the management of acute pancreatitis （AP） or chronic pancreatitis （CP） and in the prevention of post-endoscopic retrograde cholangio-pancreatography （post-ERCP） pancreatitis （PEP） up to February 2009. Twenty-two randomized, placebo-controlled, clinical trials met our criteria and were included in the review. Except for a cocktail of antioxidants which showed improvement in outcomes in three different clinical trials, the results of the administration of other antioxidants in both AP and CP clinical trials were incongruent and heterogeneous.Furthermore, antioxidant therapy including allopurinol and N-acetylcysteine failed to prevent the onset of PEP in almost all trials. In conclusion, the present data do not support a benefit of antioxidant therapy alone or in combination with conventional therapy in the management of AP, CP or PER Further double blind, randomized, placebo-controlled clinical trials with large sample size need to be conducted.

Superoxide dismutase prevents development of adenocarcinoma in a rat model of Barrett's esophagus

AIM： To test whether antioxidant treatment could prevent the progression of Barrett＇s esophagus to adenocarcinoma. METHODS： In a rat model of gastroduodenoesophageal reflux by esophagojejunal anastomosis with gastric preservation, groups of 6-10 rats were randomized to receive treatment with superoxide dismutase （SOD） or vehicle and followed up for 4 too. Rat＇s esophagus was assessed by histological analysis, superoxide anion and peroxinitrite generation, SOD levels and DNA oxidative damage. RESULTS： All rats undergoing esophagojejunostomy developed extensive esophageal mucosal ulceration and inflammation by mo 4. The process was associated with a progressive presence of intestinal metaplasia beyond the anastomotic area （9% 1st mo and 50% 4th too） （94% at the anastomotic level） and adenocarcinoma （11% 1^ST mo and 60% 4th too）. These changes were associated with superoxide anion and peroxinitrite mucosal generation, an early and significant increase of DNA oxidative damage and a significant decrease in SOD levels （P〈0.05）. Exogenous administration of SOD decreased mucosal superoxide levels, increased mucosal SOD levels and reduced the risk of developing intestinal metaplasia beyond the anastomotic area （odds ratio = 0.326; 95%CI： 0.108-0.981; P = 0.046）, and esophageal adenocarcinoma （odds ratio = 0.243; 95%CI： 0.073-0.804; P = 0.021）. CONCLUSION： Superoxide dismutase prevents the progression of esophagitis to Barrett＇s esophagus and adenocarcinoma in this rat model of gastrointestinal reflux, supporting a role of antioxidants in the chemoprevention of esophageal adenocarcinoma.

Land Management Effects on Biogeochemical Functioning of Salt-Affected Paddy Soils

Most lowlands in Northeast Thailand(Isaan region)are cultivated with rice and large areas are affected by salinity, which drastically limits rice production.A field experiment was conducted during the 2003 rainy season to explore the interactions between salinity and land management in two fields representative of two farming practices:an intensively managed plot with organic inputs and efficient water management,and one without organic matter addition.Field measurements,including pH,Eh,electrical conductivity(EC),and soil solution chemistry,were performed at three depths, with a particular focus on Fe dynamics,inside and outside saline patches. High reducing conditions appeared after flooding particularly in plots receiving organic matter and reduction processes leading to oxide reduction and to the release of Fe and,to a lesser extend,Mn to the soil solution.Oxide reduction led to the consumption of H^+ and the more the Fe reduction was,the higher the pH was,up to 6.5.Formation of hydroxy-green rust were likely to be at the origin of the pH stabilization.In the absence of organic amendments,high salinity prevented the establishment of the reduction processes and pH value remained around 4.Even under high reduction conditions,the Fe concentrations in the soil solution were below commonly observed toxic values and the amended plot had better rice production yield.

Enhanced electrocatalytic activity for H_2O_2 production by the oxygen reduction reaction: Rational control of the structure and composition of multi-walled carbon nanotubes

Hydrogen peroxide(H2O2)is a very useful chemical reagent,but the current industrial methods for its production suffer from serious energy consumption problems.Using high-activity and high-selectivity catalysts to electrocatalyze the oxygen reduction reaction(ORR)through a two-electron(2e^-)pathway is a very promising route to produce H2O2.In this work,we obtained partially oxidized multi-walled carbon nanotubes(MWCNTs)with controlled structure and composition by oxidation with concentrated sulfate and potassium permanganate at 40℃ for 1 h(O-CNTs-40-1).The outer layers of O-CNTs-40-1 are damaged with defects and oxygen-containing functional groups,while the inner layers are maintained intact.The optimized structure and composition of the partially oxidized MWCNTs ensure that O-CNTs-40-1 possesses both a sufficient number of catalytic sites and good conductivity.The results of rotating ring disk electrode measurements reveal that,among all oxidized MWCNTs,O-CNTs-40-1 shows the greatest improvement in hydrogen peroxide selectivity(from ~ 30% to ~ 50%)and electron transfer number(from ~ 3.4 to ~ 3.0)compared to those of the raw MWCNTs.The results of electrochemical impedance spectroscopy measurements indicate that both the charge-transfer and intrinsic resistances of O-CNTs-40-1 are lower than those of the raw MWCNTs and of the other oxidized MWCNTs.Finally,direct tests of the H2O2 production confirm the greatly improved catalytic activity of O-CNTs-40-1 relative to that of the raw MWCNTs.

Scenario Formation of Energy Demand and CO_2 Emissionsfor Sustainable China

Co-integration theory has been employed in this paper and Granger causes are found between urbanization rate and GDP, between capital stock and GDP. Scenario analysis of GDP is performed using the GDP model established in the paper. The energy consumptions in Germany, Japan and other developed countries are analyzed and compared with the energy consumption in China. Environmental friendly scenario of energy demand and CO2 emissions for sustainable China has been formed based on the results of comparison. Under environmental friendly scenario, the primary energy consumption will be 4.31 billion ton coal equivalence （tee） and CO2 emissions will be 1.854 billion t-c in 2050; energy per capital will be 3.06 tee that is 1.8 times of energy consumed in 2005 in China and 51% of consumed energy per capital in Japan in 2003. In 2050, the energy requirement of unit GDP will be 20% lower than that of Germany in 2003, but will be still 37% higher than that in Japan in 2003. It is certain that to fulfill the environmental friendly Scenario of energy demand and CO2 emissions is a difficult task and it needs long term efforts of the whole society, not only in production sectors but also in service and household sectors,

Vanadium oxide nanotubes for selective catalytic reduction of NO_x with NH_3

Vanadium oxide （VOx） nanostructures, synthesized by hydrothermal treatment using dodecylamine as template, were evaluated for the selective catalytic reduction of NOx with ammonia （NH3-SCR）, The effect of solvent type in the reaction mixture （EtOH/（EtOH ＋ H20）） and time of hydrolysis was studied. The obtained materials were characterized by XRD, SEM, TEM and BET, The VOx nanorods （80-120 nm diameter and 1-4 μm length） were synthesized in 25 vol% EtOH/（EtOH ＋ H20） and the open-ended multiwalled VOx nanotube （50-100 nm inner diameter, 110-180 nm outer diameter and 0,5-2 pm length） synthesized in 50 vol% EtOH/（EtOH ＋ H20）. VOx nanotuhes performed the superior NH3-SCR activity under a gas hourly space velocity of 12,000 h-1 at low temperature of 250 ~C （NOx conversion of 893g ＆ N2 selectivity of 100%）, while most of the developed Vanadia base catalysts are active at high temperature （〉350 ℃）. The superior NH3-SCR activity ofVOx nanotubes at low tem- perature is related to nanocrystalline structure, special nanotube morphology as well as high specific surface area.

Simulation for Water Quality Management in Inohana Lake Estuary, Japan

The Inohana Lake is a branch lake of the Hamana Lake. The Inohana Lake is an estuary rather than a brackish lake, and has suffered environmental problems such as eutrophication and bottom hypoxic water. In this study, the coupled hydrodynamic and ecological models （eco-hydrodynamic model） were used to construct the strategy for preventing the bottom hypoxic water and improving or recovering the water quality in the lake. Using the model input obtained from the summertime data over 1998-2002, the summer-average flow field and oxygen concentration and budget of the standard run were calculated. Remedial measures used in this study are divided into two parts： the biogeochemical and physical changes in the present situation. For the remedial measures including the biogeochemical changes in the present situation, the simulations considering the reductions of the nutrient inputs from the river, main lake （land） and bottom sediment, and the sediment oxygen demand （SOD） were carried out. For the remedial measures including the physical changes, the 50 and 100 m extensions of the inlet width were considered in the model runs. These simulated results were compared in terms of changes in the dissolved oxygen （DO） concentration and oxygen budget in the bottom layer in the Inohana Lake. There was no significant change in the DO concentration and oxygen stock in the simulations for the reduction of the nutrient inputs from the land and bottom sediment, however increases in those in the simulations for the reduction of SOD. When SOD was reduced by 50%, the bottom DO concentration increased by approximately 2 mg/L and the oxygen stock in the bottom layer increased by 47% comparing the present situation （the standard run） of the lake. The simulation results for inlet width extension showed that the extension of width makes the DO concentration and oxygen stock lower. The remedial measures for the sediment control were proposed to prevent the bottom hypoxia and manage the water quality.

A Case Study of the Safety Management in WWTPs

Wastewater treatment plants （WWTPs） can represent risks source for human health and environment, due to the use of chemicals and substances produced by the treatment process. In particular, considering a conventional urban wastewater treatment plant, two case studies have been considered in this paper： the phase of disinfection with Peracetic Acid （PAA）, used as reactant and the sludge anaerobic digestion, generating biogas. The aim of the experience is to find out some management suggestions that could make safer these sections of a WWTP.

Vertically oriented TiO_2 nanotube arrays with different anodization times for enhanced boiling heat transfer

Pool boiling of saturated water on a plain Ti surface and surfaces covered with vertically-oriented TiO2 nanotube arrays(NTAs) has been studied.The technique of potentiostatic anodization using non-aqueous electrolytes was adopted to fabricate three types of TiO2 NTAs distinguished by their anodization time.Compared to the bare Ti surface,the incipient boiling wall superheat on the TiO2 NTAs was decreased by 11 K.Both the critical heat flux and heat transfer coefficient of pool boiling on the TiO2 NTAs were higher than those from boiling on a bare Ti surface.The measured maximum critical heat flux and heat transfer coefficient values were 186.7 W/cm2 and 6.22 W/cm2K,respectively.Different performances for the enhancement of heat transfer by the three types of TiO2 NTAs were attributed to the different degrees of deformation in the nanostructure during boiling.Long-term performance of the nanomaterial-coated surfaces for enhanced pool boiling showed degradation of the TiO2 NTAs prepared with an anodization time of 3 hours.

Thermal Modeling and Management of Solid Oxide Fuel Cells Operating with Internally Reformed Methane

A detailed three-dimensional mechanistic model of a large-scale solid oxide fuel cell(SOFC) unit running on partially pre-reformed methane is developed. The model considers the coupling effects of chemical and electrochemical reactions, mass transport, momentum and heat transfer in the SOFC unit. After model validation, parametric simulations are conducted to investigate how the methane pre-reforming ratio affects the transport and electrochemistry of the SOFC unit. It is found that the methane steam reforming reaction has a "smoothing effect", which can achieve more uniform distributions of gas compositions, current density and temperature among the cell plane. In the case of 1500 W/m^2 power density output, adding 20% methane absorbs 50% of internal heat production inside the cell, reduces the maximum temperature difference inside the cell from 70 K to 22 K and reduces the cathode air supply by 75%, compared to the condition of completely pre-reforming of methane. Under specific operating conditions, the pre-reforming ratio of methane has an optimal range for obtaining a good temperature distribution and good cell performance.

Synthesis and Characterization of Niobium-doped TiO_2 Nanotube Arrays by Anodization of Ti-20Nb Alloys

Well crystallized niobium-doped TiO; nanotube arrays （TiNbO-NT） were successfully synthesized via the anodization of titanium/niobium alloy sheets, followed with a heat treatment at 550 ℃ for 2 h. Morphology analysis results demonstrated that both the titanium/niobium alloy microstructure and the dissolution strength of electrolyte played major roles in the formation of nanotube structure. A single-phase microstructure was more favorable to the formation of uniform nanotube arrays, while modulating the dissolution strength of electrolyte was required to obtain nanotube arrays from the alloys with multi-phase microstructures. X-ray diffraction （XRD） and X-ray photoelectron （XPS） analysis results clearly demonstrated that niobium dopants （Nb^5＋） were successfully doped into TiO2 anatase lattice by substituting Ti^4＋ in this approach.

Plinthite and Its Associated Evolutionary Forms in Soils and Landscapes:A Review

At elevated temperature regimes and abundant precipitation, mobilization and accretion of weathered iron oxides are promoted especially in a reduced environments in the tropics. This may lead to the formation of plinthite, which hardens irreversibly upon repeated wetting and drying to form petroplinthite. The need for this review stems from the seemingly dearth of information on the subject and a need to clarify different terms used in describing plinthite. We review various research works on plinthite and its associated pedogenic forms in the tropics. Furthermore, we proffer recommendations as to the most appropriate land use management practices that could help minimise the environmental and agronomic problems associated with plinthite and its related pedogenic forms. Parent material, temperature, seasonality and geomorphology are critical factors that influence soil water regime which in turn affect the pedogenesis of plinthite. Soil pH and mineralogy are additional factors that could also promote plinthite formation. Fossil plinthic soils are potential proxies for palaeoenvironmental reconstruction. Measures used in the management of plinthic soils include mechanically breaking the hardpans and the use of organic and inorganic amendments to modify the structure and chemistry of the soils. Avoidance of practices that would predispose soils to erosion would also prevent plinthization. We call for the relinquishment of the term ＂[aterite＂ which is a generM term for all forms of iron oxide-enriched earthy materials as used for plinthite. Plinthic horizon should also be incorporated into the United States Department of Agriculture Soil Taxonomy in view of its growing importance in soils.

An Advance in Complete Oxidation of Formaldehyde at Low Temperatures

Editor＇s comments Formaldehyde （HCHO） emitted from chemical manufacturing plants including methanol-gasoline/diesel fuel vehicles and the construction and decoration materials is one of the major air pollutions, which induces photochemical pollution and hazards human health. Great efforts have been made for the reduction or control of the emission of HCHO to satisfy the stringent environmental regulations. Now, a new study supported by the National Natural Science Foundation of China reports mesoporous manganese oxide with novel nanostructures for the decomposition of HCHO. The obtained manganese oxide nanomaterials showed high catalytic activities for oxidative decomposition of HCHO at low temperatures. Complete conversion of HCHO to CO2 and H2O were achieved, and no harmful by- products were detected in effluent gases. The catalytic activities of these nanomaterials are significantly higher than those of previously reported manganese oxide octahedral molecular sieve （OMS-2） nanorods , MnO x powders, and alumnina-supported mangnaese-palladium oxide catalysts. These results provide a new route for the removal of HCHO and other air pollutions.

Full-solution-processed high mobility zinc-tin-oxide thin-film-transistors

The full solution-processed oxide thin-film-transistors(TFTs) have the advantages of transparency, ease of large-area fabrication, and low cost, offering great potential applications in switching and driving fields, and attracting extensive research interest. However, the performance of the solution-processed TFTs is generally lower than that of the vacuum-deposited ones. In this article, the full-solution processed TFTs with zinc-tin-oxide(ZTO) semiconductor and aluminium(Al_2O_3) dielectrics were fabricated, and their mobilities in the saturation region are high. Besides, the effect of the Al_2O_3 dielectrics' preparation technology on ZTO TFTs' performance was studied. Comparing the ZTO TFTs using the spin-coated Al_2O_3 dielectrics of 1–4 layers, the ZTO TFT with 3-layer Al_2O_3 dielectrics achieved the optimal performance as its field-effect carrier mobility in the saturation region is 112 cm^2/V s, its threshold voltage is 2.4 V, and its on-to-off current ratio is 2.8×105. This is also the highest reported carrier mobility of the solution-processed ZTO TFTs.